Chain saws, harvesters and the like are typically used in conjunction with saw chains to cut wood and other material. Saw chains, which are a collection of components that typically include cutter links, side links, center links, and/or drive links, are driven around a guide bar by the chain saw or harvester. Due to the speeds at which the saw chain is driven, the material being cut and the forces encountered, the chain drive links and guide bar grooves need to be well lubricated. It has been a constant challenge to not only properly lubricate on both sides of the chain, but also along the entire length of the guide bar.
Of the many features that have been implemented over the years to try and improve lubrication, locating a through hole in the body of the drive link has proven to provide the best lubrication solution. Invented by Blount Inc, and referred to as LUBRIWELL™, the hole is designed to carry lubricating oil along a guide bar groove, thus reducing sliding friction and reducing bar and chain wear. Secondarily, the through hole may carry wood chips that are oil soaked, thus promoting a wicking action to facilitate spreading lubrication oil along the bar groove and to other components of the cutting system. However, a draw back of the through hole is that with some designs and in some cutting conditions, the hole may become clogged, for example, with wood chips and/or other debris. The chips can be so compacted that friction is created between the chips and the bar groove, thus generating resistance that can exceed the available horsepower of the saw and thus hamper cutting and performance.